Process for manufacturing jailbar steel ingots



Dec'. 1, 1931. M. RA TREMBOUR ET Al. 1,834,750

PROCESS FOR MANUFACTURING JAILBAR STEEL INGTS Filed April 18l 1950 Patented Dec. 1, 1931 MAX R. TREMBOUR OF BEAVER BOROUGH,

PATENT OFFICE AND JOHN A. AUTH, OF MOON TOWNSHIP,

[BEAVER COUNTY, PENNSYLVANIA, ASSIGNORS T COLONIAL STEEL COMPANY, OF

PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA PROCESS FOR MANUFACTURING JAILBAR STEEL INGOTS Application filed April 18 Jailbar steel is used in detention institu-*S tions, such as jails and prisons, and also for the protection of banks. and other depositaries of valuables, and the like. g T o adequately serve such purposes the bars 'or plates must be difficult to break or shatter as by the blows `of a- Sledge hammer and must also be diicult to cut as by a ile or saw. mi' Thus jailbar steel is characterized by a body of relatively soft steel, which `cannot bereadily shattered or broken, and inserts of relatively hard Steel which cannot be readily cut. i

The relative positioning of the hard steel inserts in thesoft 'steelbody is a feature of the greatest importance but difficult to-accomplish.

It is necessary to place the inserts as near 2a as possible to the Surface so that the cutting of the soft steel to a material extent may be prevented. Otherwise the soft steel body might be cut or notched andthe inserts Shat- .tcrcd or broken by` a blow at the notched portion. Again, if the inserts be placed directly at the surface of the soft steel thuey may be first shattered and the soft steel then cut through. Again this placement of the inserts presents practically insurmountable difficultics in manufacturing dueto cracking of the ingot. i

Again` inserts`which are relatively. posi Ytioned in an improper manner are-'exposed to `individual attack and may be cut through one at a time.l

@he of the characteristic features of our invention is a jailbar whose inserts are placed nearA but notl at the surface of the soft steel so that no material cutting of the latter may 40 be accomplished Without encountering and attacking the inserts, and also whoseinserts are relatively positioned in such manner that they cannot be attacked and cut one at a time. y

rlhe casting of a jailbar ingot is'a difficult operation owing to the number of inserts which must be incorporated in thekingot and near the outer surfaces Iof the latter. and which must be uniformly covered and inclosed bythe soft steel.

, T930. Serial No. 445,39s.`

IVe have therefore Ainvented a new andimproved process for producing such ingots. One of the characteristic features of our improved process is the bottom-casting of the 'soft steel into a vertically disposed mold.`

` Te irst assemble the hard steel inserts into rigid relationship with each other, forming what might be termed a cage, a support. such as a steel ring being welded or otherwise secured to each end of the inserts so as to hold them in proper position in the mold. The rings are of soft steel Similar to the soft steel which isrto form the body ofthe ingot.

The cage thus formed *is then inserted downwardly into the mold and suspended from above'ther'ein. The ends ofthe cage stop short ofthe upper 'and lower ends of the mold so that the ends of the inserts are entirely covered by the molten soft steel.

' The ingot is then removed from the mold and rolled or worked to final form in the usual manner.

In the accompanying drawings, wherein we have illust-rateda practical embodiment of the principles of our invention, Fig. 1 is an elevation of one-half of a split ingot mold with the cage of inserts suspended therein, the cage being shown in 'vertical section. Fig. 2 is a similar but broken View showing the soft metal body cast in the mold. Fig. 3 is a cross-sectional View taken along the line 3-v-3in. Fig,.1. i

Fig. 4 is asimilartvie'w .taken along the line 4-4 in Fig.

Fig. is a cross-sectional view of a round jailbar rolled from the ingot showny in Figs. 2 and 4. i

Fig. A6 is a cross-sectional View of a plate rolled from the yingot illustrated in Figs. 2 and 4.

`Referring to the drawings, la and 1b represent the two parts of a vertical split ingot mold mounted on a. base ,2 which is provided with a channel 3 and port 4 for the bottomcasting of the molten metal into the mold.

5 represents the hard steel inserts which may be and preferably'are of chrome-manganese alloy. The bars are of proper erosssectional arca to provide the proper area in the finished jailbar, such as shown in Fig. 5. 100

'I'he bars 5 are assembled and secured together in proper relation before they are inserted into the mold.

surfaces against which the inserts are welded.

The ingots are usually castwith a substantially square or rectangular cross-sec-` tional shape and thus the rings are of the proper shape to properly position the inserts 40 Cutting the inserts.

i the soft steel body 9 of the ingot is ofthe,

relative to the body of soft metal in which the inserts are to be enveloped.

The cage thus formed of hard steel inserts and soft steel' rings is suspended from above in the otherwise empty ingotmold with theV lower end of' the cage spaced above the bottom of the mold and the upper end of the cage below the top of thc mold.

In practice we suspend the cage in place by means of steel struts or bars 7 placed on top of the mold, and steel hooksS whose upper ends are hooked over the bars 7 and whose lower ends are hooked over the top ring 6. Four of such hooks 8 may be used, two suspended'froin each strut 7. n The soft metal 9, which is usually low carbon steel, is then bottom-cast in the mold and filled up to the top of the mold or abovethe n upper end of the inserts 5. The soft metal envelope .covers the Ilower end of the inserts and also coversthe upper ends of the inserts to` a. sulicient degree to permit the pipes to encounter anotherA insert or inserts, thus renr dering the attempt to sever the inserts pracftically abortive.

In Fig. 6 We the soft steel body being indicated at 9b and n have illustrated the ingot rolled out into the form of a flat bar or plate,

with the wall, of the mold, and casting the mold full of soft steel. y

2. The process of manufacturing jailbar ingots which comprisesassembling a plurality of hard steel inserts into a cage, having its center open throughout its length, by securing the inserts to the outer perimetrical y l surfaces of rings of vsoft steel, suspending said cage'in a vertical position in a vertically disposed mold with the inserts out of contact with the wall of the mold and the ends of the inserts being spaced within the top and bottom o'f the mold, and casting the mold full of soft steel, the soft steel covering both ends of theiinserts.

- Signed at Monaca,-Pa., thislthday ot" April` 1939. y

MAX R. TREMBOUR. JOI-IN be cut off the upper end of the ingot without When the ingot has hardened, the'split i mold is opened and the ingotremoved, and it isthen worked in they usual manner to final form, such for instance as illustrated in Fig. 5 wherein the reduced inserts 'are shown at 5a and the soft steel body at 9a. .In the works The positioning ofthe inserts 5 relative'to i greatest importance. We have illustrated oiir improved arrangement and it will be there noted that in the finished'bars these inserts are placed near but notat the surface of the soft steel body, so that'no material cutting of the soft steel can be accomplished before the file, saw of other cutting tool encounters one or more of the inserts. Again the soft steel cannot be notched sufficiently to allow the inserts to be shattered by a blow. L(

It will be noted that the inserts are suficiently numerous and are .so placed relative to each other that no one insert may be separately attacked. In other words before one '5 insert can be materially cut into the tool will 

